Marine propulsion lower unit



June 3, 1969 w. J. SHIMANCKAS 3,447,504

MARINE PROPULSION LOWER UNIT Sheet Filed April 28. 1966 WzZ/(ari June 3, 1969 w, J. SHIMANCKAS MARINE PROPULSION LOWER UNIT Sheet Filed April 28. 1966 Mum Mam/far WWW"! 5km? United States Patent 3,477,504 MARINE PROPULSION LOWER UNIT William J. Shimanckas, Waukegan, Ill., assignor to Outboard Marine Corporation, Waukegan, Ill., a corporation of Delaware Filed Apr. 28, 1966, Ser. No. 545,934 Int. Cl. B63h 23/04, 23/08, 21/26 U.S. Cl. 115-34 14 Claims ABSTRACT OF THE DISCLOSURE Disclosed herein is a marine propulsion device comprising a lower unit including therein a rotatably mounted propeller shaft extending only at one end from said lower unit, and a second shaft rotatably mounted in said lower unit and extending in acute angular relation to said propeller shaft, a third shaft rotatably mounted in the lower unit, and bevel gearing connections between the propeller shaft and between the second and third shafts.

The invention relates generally to a lower unit for marine propulsion devices. More particularly, the invention relates to propeller drive trains in said lower units and to streamlined outer configurations for said lower units.

It has been common in marine propulsion lower units to connect a generally vertical crankshaft or drive shaft to a generally horizontal propeller shaft by means of a reversing transmission or other gearing located in a gear box at the lower end of the lower unit. Such right angle drive connections have resulted in gear boxes of substantial width which creates considerable drag or resistance to travel through the water.

One principal object of the invention is the provision of a marine propulsion lower unit having a lower part or gear box which is submerged in water during normal operation and which is of reduced thickness as compared to prior lower units of comparable power transmitting capacity.

Another principal object of the invention is the provision of a generally Z-shaped drive train which affords a relatively narrow design for the lower end of the lower unit, thereby substantially reducing drag during opera tion in the water. More specifically, the invention herein disclosed provides a drive train including a principally horizontally extending propeller shaft, a second or inclined shaft extending upwardly at an acute angle to the propeller shaft, 2. third shaft extending principally horizontally above the propeller shaft and in acute angular relation to the inclined shaft, bevel gearing connecting each of the propeller and inclined shafts and the inclined and third shafts, and a transmission connecting the third shaft to the engine crankshaft. As a result of this configuration, the lateral bulkiness generally associated with such transmissions and/or with associated water pumps is located above the propeller shaft in a part of the lower unit not normally submerged in water.

Other objects and advantages of the invention will become known by reference to the following description and accompanying drawings in which:

FIGURE 1 is a fragmentary, front elevational view of one embodiment of a marine propulsion lower unit incorporating various of the features of the invention;

FIGURE 2 is a fragmentary sectional view taken generally along line 22 of FIGURE 1;'

FIGURE 3 is a fragmentary front elevational view of another embodiment of a marine propulsion lower unit incorporating various of the features of the invention; and

FIGURE 4 is a fragmentary sectional view taken generally along line 4-4 of FIGURE 3.

Patented June 3, 1969 Shown in FIGURE 1 is a lower unit 11 of a marine propulsion device, such as an outboard motor or a stern drive unit. The lower unit 11 includes a housing or strut 13 which includes a part 15 normally located below the water line. As shown in FIGURE 1, the lower unit part 15 has a reduced thickness as compared to the upper part 19 of the lower unit. Such reduced thickness is made possible by the use of a drive train 21 which connects a propeller shaft 23 and the engine crankshaft or an extension thereof in the form of a driveshaft 25.

More particularly, the drive train 21 comprises, in addition to the propeller shaft 23 and the driveshaft 25, an inclined shaft 27, a third or principally horizontal or upper shaft 29, bevel gearing 31 drivingly connecting the propeller shaft 23 and the inclined shaft 27 and bevel gearing 33 drivingly connecting the inclined shaft 27 and the third shaft 29, together with a clutch or transmission 35 between the drive shaft 25 and the third shaft 29.

Still more particularly, the propeller shaft 23 is journalled in the part 15 by spaced bearings 37, 38 and 39 and extending from the lower unit 11 as shown in FIG. 2 at only the rearward end. Mounted at the rearward end of the propeller shaft is a propeller 41. At its forward end, between the bearings 37 and 38, the propeller shaft includes a portion 43 which is of reduced diameter and which has non'rotatably fixed thereon a bevel gear 45 which is only slightly beveled as compared to a gear of cylindrical form.

The inclined shaft 27 extends upwardly and rearwardly in the part 15 and is journaled, adjacent its ends, by bearings 47 and 49. At its ends, the inclined shaft includes reduced diameter portions 51 and 53 which respectively carry bevel gears 55 and 57 similar to the bevel gear 45. The bevel gears 55 and '57 are retained in fixed, nonrotatable relation to the inclined shaft by respective nuts 59 and 61. As can be seen from FIGURE 2, the bevel gears 45 and 55 are in meshed relationship.

The third shaft 29 extends principally horizontally above the upper end of the inclined shaft and is journalled by three spaced bearings 63, 65 and 67. More specifically, the bearing 63 supports a reduced diameter rearward end portion 69, while the bearing 65 supports the hub 71 of a bevel gear 73 which is splined on an intermediate part 75 of the third shaft 29 and which is meshed with the bevel gear 57 at the upper end of the inclined shaft 27. The third bearing 67 supports a hub 77 of a bevel gear 79 which is non-rotatably fixed to the forward end of the third shaft 29 and which constitutes one part of the transmission 35.

The drive shaft 25 is journalled in the lower unit, at least in part, by vertically spaced bearings 81 and 83. As shown in FIG. 2 both the shafts 25 and 29 terminate with at least one end in the lower unit 11.

While various transmissions, and even a permanently meshed drive connection between the drive shaft 25 and the third shaft 29 can be employed, in the disclosed construction, the transmission 35 affords forward, neutral, and reverse drive conditions. Accordingly, in the embodiment shown in FIGURE 2, the transmission 35 includes, in addition to the bevel gear 79, a pair of bevel gears and 87 which are co-axially, rotatably mounted on the drive shaft 25 between the bearings 81 and 83 and in meshing engagement with the bevel gear 79. Not rotatably but axially slidably carried on the driveshaft 25 between the bevel gears 85 and 87 is a clutch dog 89. Included on each end of the dog 89 and on the bevel gears 85 and 87 are inter-engaging lugs 91 providing for selective driving engagement of the dog 89 with the respective bevel gears 85 and 87 in response to movement of the dog 89 from a centered neutral position toward one or the other of the bevel gears 85 and 87.

Suitable means are provided for shifting the dog 89 axially of the shaft 25. Such means includes a fork 93 which extends from the dog 89 and is connected to a throw rod 95 which is carried for axial movement by bearings 97 and 99. Vertical movement of the throw rod 95 suflicient to engage the dog 89 with either of the bevel gears 85 and 87 is provided by means including a rocker arm 101 which, intermediate its ends, is pivotally mounted in the lower unit 11 and which, at its oppositeends, is connected by pivotal lost motion connections with each of the throw rod 95 and a link 103 leading to a remote operator (not shown).

In the event it is desired to provide the lower unit 11 with means for pumping water for an engine cooling system, the lower unit 11 includes passage means affording water flow to a water pump 111 located immediately above the transmission 35. In this regard, the lower unit part includes a series of water inlets 113 which are located generally below the propeller shaft 23 and which communicate with a duct or flow passageway 115 extending, at least in part, parallel to the inclined shaft 27. The duct 115 communicates through another duct 117 with a cavity 119 which is in communication with a recirculating pipe 121 and with the supply inlet of the pump 111. Any suitable engine cooling system can be employed.

As can be seen from FIGURES l and 2, the lower unit 11 is constructed of several pieces to afford access to, and assembly of, the drive train 21. More specifically, the lower unit 11 includes a strut portion 125 which is connected, by a series of bolts 127, only two being shown, to a combined gear box and skeg 129. Access to the transmission 35 can be obtained by removing a circular plate 131 retained in position by a bolt 133 and a removable inner plate 135. Access to the area of the bevel gears 45 and 55 can be obtained by removing a nose piece 137 which is connected by bolts 139 to the combined gear box and skeg 129.

Shown in FIGURES 3 and 4 is another embodiment of a marine propulsion lower unit 211 including a generally horizontal propeller shaft 223, an inclined shaft 227, a generally horizontal upper shaft 229, and a generally vertical drive shaft 225. As can be readily observed, the shafts 223 and 227 are drivingly connected by respective bevel gears 245 and 255 while the shafts 227 and 229 are similarly connected by respective bevel gears 257 and 273. The horizontal propeller shaft 223 is supported by spaced bearings 237, 238, and 239. The inclined shaft 227 is supported by spaced bearings 247 and 249. In addition, three spaced bearings 263, 265, and 267 are provided to support the upper horizontal shaft 229.

In the construction shown in FIGURES 3 and 4, the shafts 2.29 and 225 are connected by a fragmentarily illustrated transmission 235 which is generally conventional except for being located at the upper horizontal shaft 229 instead of the propeller shaft 223. Because of various preexisting patents, as for instance, Patent 3,145,688, which shows such transmissions, a detailed explanation is not included.

As in the embodiments shown in FIGURES 1 and 2, means are provided for supplying water to a water pump in the event that such a feature is desired. -In this regard, the lower unit part 215 includes a duct 315 having a first segment 317 in a nose piece 337 which is bolted to the adjacent portion of a combination gear box and skeg 329. The duct 315 also includes a second segment or portion 319 which communicates with an annular portion 321 surrounding the bearing 263. In turn, the portion 321 communicates with still another portion 323 leading to the water pump which, as in the embodiment shown in FIG- URES 1 and 2, can be located immediately above the transmission 235.

Each of the lower units includes, as shown best in FIGURES 1 and 3, respective cavitation plates 371 and 373 to assist in providing optimum propeller performance.

Various of the features of the invention are set forth in the following claims:

What is claimed is:

1. A marine propulsion device comprising an outboard lower unit normally disposed partially under water and including therein a rotatably mounted propeller shaft extending only at one end from said lower unit, a second shaft rotatably mounted in said lower unit and extending in acute angular relation to said propeller shaft, a third shaft rotatably mounted in said lower unit in spaced relation to said propeller shaft and extending in acute angular relation to said second shaft and having one end terminating within said lower unit, and bevel gearing connections between said propeller shaft and said second shaft and between said second and third shafts.

2. A marine propulsion device comprising a lower unit disposed partially under water in operating position and including therein a rotatably mounted propeller shaft, a second shaft rotatably mounted in said lower unit and extending in acute angular relation to said propeller shaft, bevel gearing connections between said propeller shaft and said second shaft, a third shaft rotatably mounted in said lower unit in spaced relation to said propeller shaft and extending in acute angular relation to said second shaft, bevel gearing connections between said second and third shafts, a fourth shaft rotatably mounted in said lower unit and extending transversely of said third shaft, and a clutch between said third shaft and said fourth shaft.

3. A marine propulsion device in accordance with claim 2 wherein said clutch includes a first bevel gear fixed to one of said third and fourth shafts, second and third spaced bevel gears meshed with said first bevel gear and coaxially rotatably mounted on the other of said third and fourth shafts, a dog slidably splined to said other of said third and fourth shafts between said second and third bevel gears, interengageable lugs on said dog and said second and third bevel gears for selective engagement in response to axial movement of said dog on said other shaft, and means for axially displacing said dog between positions selectively engaging said lugs on said dog and on said second and third bevel gears to aiford reversible driving connection between said third and fourth shafts.

4. A marine propulsion device comprising an outboard lower unit including a lower part normally submerged in water during operation and an upper part extending upwardly from said lower part, said lower part having a thickness less than said upper part, a propeller shaft rotatably mounted in said lower part, a second shaft rotatably mounted in said lower unit and extending in acute angular relation to said propeller shaft, bevel gearing connections between said propeller shaft and said second shaft, a third shaft rotatably mounted in said lower unit in spaced relation to said propeller shaft and extending in acute angular relation to said second shaft, and bevel gearing connections between said second and third shafts.

5. A marine propulsion device in accordance with claim 4 wherein said lower unit includes a water pump located in said upper part and a duct at least partially located in said lower part and leading to said water pump from an inlet located in said lower part.

6. A marine propulsion device in accordance with claim 5 wherein said inlet is located forwardly of said gearing clonnection between said propeller shaft and said second s aft.

7. A marine propulsion device in accordance with claim 5 wherein said inlet is located below said propeller shaft.

8. A marine propulsion device in accordance with claim 5 wherein said duct is at least partially located forwardly of said second shaft.

9. A marine propulsion device in accordance with claim 5 wherein said duct is at least partially located rearwardly of said second shaft.

10. A lower unit for a marine propulsion device, said lower unit comprising a lower part normally submerged in water during operation and an upper part extending upwardly from said lower part, said lower part having a thickness less than said upper part, a propeller shaft rotatably mounted in said lower part, an inclined shaft rotatably mounted in said lower unit and extending in acute angular relation to said propeller shaft, a generally horizontal drive shaft rotatably mounted in said upper part and extending in acute angular relation to said inclined shaft, a generally vertical drive shaft rotatably mounted in said upper part, a first bevel gearing connection in said lower part between said propeller shaft and said inclined shaft, a second bevel gearing connection in said upper part between said inclined shaft and said generally horizontal shaft, a first bevel gear fixed to one of said generally horizontal and generally vertical drive shafts, second and third spaced bevel gears meshed with said first bevel gear and coaxially rotatably mounted on the other of said generally horizontal and generally vertical drive shafts, a dog slidably splined to said other of said generally horizontal and generally vertical drive shafts, intergengageable lug means on said dog and on said second and third bevel gears for selective engagement in response to axial movement of said dog on said other drive shaft, means for axially displacing said dog between positions selectively engaging said lug means to afiord reversible driving connection between said generally horizontal and generally vertical drive shafts, a water pump located in said upper part, and a duct at least partially extending in said lower part rearwardly of said inclined shaft and leading to said water pump from an inlet located in said lower part.

11. A lower unit for a marine propulsion device, said lower unit comprising a lower part normally submerged in water during operation and an upper part extending upwardly from said lower part, a propeller shaft rotatably mounted in said lower part, an inclined shaft rotatably mounted in said lower unit and extending in acute angular relation to said propeller shaft, a generally horizontal drive shaft rotatably mounted in said upper part and extending in acute angular relation to said inclined shaft, a generally vertical drive shaft rotatably mounted in said upper part, a first bevel gearing connection in said lower part between said propeller shaft and said inclined shaft, a second bevel gearing connection in said upper part between said inclined shaft and said generally horizontal shaft, a first bevel gear fixed to one of said generally horizontal and generally vertical drive shafts, second and third spaced bevel gears meshed with said first bevel gear and coaxially rotatably mounted on the other of said generally horizontal and generally vertical drive shafts, a dog slidably splined to said other of said generally horizontal and generally vertical drive shafts, interengagable lug means on said dog and on said second and third bevel gears for selective engagement in response to axail movement of said dog on said other drive shaft, and means for axially displacing said dog between positions selectively engaging said lug means to afford reversible driving connection between said generally horizontal and generally vertical drive shafts.

12. A lower unit for a marine propulsion device, said lower unit comprising a lower part normally submerged in water during operation and an upper part extending upwardly from said lower part, a popeller shaft rotatably mounted in said lower part, an inclined shaft rotatably mounted in said lower unit and extending in acute angular relation to said propeller shaft, a generally horizontal drive shaft rotatably mounted in said upper part and extending in acute angular relation to said inclined shaft, a generally vertical drive shaft rotatably mounted in said upper part, a first bevel gearing connection in said lower part between said propeller shaft and said inclined shaft, a second bevel gearing connection in said upper part between said inclined shaft and said generally horizontal shaft, and clutch means connecting said generally horizontal and generally vertical drive shafts.

13. A marine propulsion device comprising an out board lower unit including therein a rotatably mounted propeller shaft, a second shaft rotatably mounted in said lower unit and extending in acute angular relation to said propeller shaft, a third shaft rotatably mounted in said lower unit and extending at substantially a right angle to said propeller shaft, bevel gearing connections between said propeller shaft and said second shaft and a clutch between said third shaft and said second shaft.

14. A marine propulsion device comprising an outboard lower unit disposed partially in water during normal operation and including therein a rotatably mounted propeller shaft, a second rotatably mounted shaft extending in acute angular relation to said propeller shaft, bevel gearing connections between said propeller shaft and second shaft, a third shaft rotatably mounted in said lower unit in spaced relation to said propeller shaft and extending in acute angular relation to said second shaft, and a clutch between said second and third shafts.

References Cited UNITED STATES PATENTS 2,528,628 11/1950 Whitney -18 1,778,970 10/ 1930 Cotta et al. 192-3.5 2,164,487 7/ 1939 Beckjord 11S--34 X 3,164,121 1/1965 Alexander 115-17 TRYGVE M. BLIX, Primary Examiner.

US Cl. X.R. 1l517 

